Coal-screen.



P. J. 'ALWARL COAL SCREEN.

APPLICATION FILED :UNE 1916.

- Lzomez.

P. J. ALWART.

y COAL SCREEN.

APPLICATION FILED JuNE 7, 191s.

1,207,262.v Patented Dec. 5,1916.

3 SHEETS-SHEET 2.

IOT

/ 2o Z0 (j m um P. J. ALWART.

- com SCREEN. APPLICATION msn JUNE 19m.

1,207,262. Patented Dee. 5,1916

-38, in the the drawings, said gearing comprises a around a rod 34, which rod projects beyond the 'ends of the gate and is pivotally secured on "the, side members by bearing brackets 35V. One or both of the gates 32, 33 may be weightedin order to obtain a more effective separation of the dust and smallerr particles from the coal, and such a construction is shown in Figs. 7 and 8, where a bar 36. is Shown as secured near the lower edge ofd the gate by bolts and nuts 37, the bolts extending through vertically extending slots ate in order `to afford adjustment of sai weight toward or away from the pivot thereof. t

At the lower end of the screen is a ho per vportion 49, which may be used when ging the coal, and said hopper may'be sup ported by a chain 50,V running to some stationary portion of the structure. A swinging gate 51,?atthe lower end of the hopper 49, serves to check the flow of coal when one bag is'removed andanother one is replaced on the end of the hopper. Below` each screenis a chute 52, for conveying the ne particles away from the clean coal. The cam shafts 24, ofthe screens may be driven from a suitable motor 39, by any suitable form of gearing and as shown in 1nion 40, upon the motor shaft, a gear w ieel '41, upon a shaft d2 journaled in hearings secured on the framework of the device.

l'pon each cam shatt 24, and on the shaft +2, are sprocket wheels 43, il, which are connerted b v sprocket chains l5. For c'ontrolling the motor Elf), l" )rovide a knife switch 4G, which is operated by operating handles 47, and a conneeting'rml 4S, as clearly shown in Fig. 1,01 the drawings.

In the o )eration of this device, the hopper 1l, is filled or partially filled with coal, the door 1l, of the screen or vscreensI to he used is raised suttieiently to pernlit a free How of the coal to the screen; the screen being stationary, the coal runsl down to the first gate 31, where it is'checked. lVhen however. the motor 39, is started and the screen is vi-` hrated, the gates 31, 3?, are swung upward each time the screen moves upward, and this action upon said gates, together with the shaking of the coal and weight thereof` causes the upper gate to open slightly, permittin'g a quantity of the coal to run down tothe next-gate where it is held vbark momentarily, after which said gate opens under the influence of the vibrating aetion'oi the screen and the weight of' the coal as it neemnulates. Thissame action takes place Aat the third gate. By reason of the gates,

the coal is retained on the screen for a greater length ottime than it would be if.y the coal were to run down the screen unprovided withvgates, and in this way as much as T5 per cent. of the dust and fine particles 25 of coal are separated from the larger pieces,

and practicallv clean coal is delivered from the screen. "o stop the flow of coal the motor is stopped,`and lis-soon as the screen ceases to vibrate, the coal above the gates remains on the screen and does not run down, l l I am aware that shaking screens are old. and also stationary screens with gates are old, but these screens do not accom lish the result which I am able to accomp ish with my vibratingl screen and swinging gates. When this device is properl set for oierntion, it does not require a s illed Aattendant to handle it, since all that is necessary for the driver to do is start the motorby means of the handle 47,'and the coal will run down the screen, but will be held back between the gates lon enough to free itself of the coal dust an fine particles More or less variation of the exact details of construction is possible without' departingA from the spirit; of this invention, and I desire', therefore, not to limit myself to the exact form of construction shown and dey scribed', but intend in the 4followin to point out all of the invention isclosed herein. l i Y I claim as new andfdesire to secure by Letters Patent:

1. Screening apparatus, comprising a ho claims per having a discharge opening, a steep y of inflexible material hingedly sup orted on said side frame members above t e screen with their lower edges adapted to rest on said screen, said gates operating to retard the flow of material while the screen is being vibrated, but oaerating to arrest the flow when the vibrating means are stopped.

2. Screening apparatus, comprising a hopper havingan inclined bottom, a discharge opening at the lower end of said, bottoin,4 a door for regulating the size of said opening, a steeply inclined vibratory screen', yproject,- ing from said opening, power driven. means for vibrating said screen, stationairily supported side framev members extending along the sides of said Screen, and a plurality of transverse material retarding and arresting gates formed of inflexible material hingedly supported on said side Vframe members above said screen with their lower edges resting thereon., said gates being adapted to hohl back the in" """al to be screened, when the screen is st1 ionarv. f

steeply inclined hin dly supported at itsupper end,l a caii'i edile end for vibratin said screen, a power driven shaftv for t ecam, stationarily supacent its lower 3. Screening, elianism, comprising a ported side frame membersA extending along thesides of Said Screen', and a t ansvvrsely A extending gate 4formal if inflexible nmterial liingedly' supported on'saifl'sideframe mem-. bers above the screen with its lower edge' restin on the sreen, said gate being ar- -range to ,a1-reet tliecoal when the screen is Stationary.

4. Screening mechanism, comprising a side members with their lmrar vllges resting on said "screen, the lowvrmosl gate lw1l1; lweighted.

Screening lnol'lulliisnx. vl-nnprisingr n hopper having 111 invlinall bottom nml :r

discharge opening; at tlwvlmrvr rml ol ,mill bottom, an inclined scrl-vn' llnamlly mfurwl all its,l upper and, a pow-ar lrwn i lmlt: |1nller the lower and of v:will srrram rams on saillie-haft supporting saill svrvea nml adapted to vibrato lt. Stallman-r Silla' nnmlwrs lor Suid Svi'cml, tl':|n:-'.\vt'.\vl extending material rotardinlgf- :unl arresting galas formed nl inflexiblv lmltvtinlvliillgwlllr srmiroll to :mill sidemumllors will Llnr lmrar allg'os rah-ting' on sailfsvl-vl-n. nml an mljastalily nimmtml Weight on llw lowvlmosl anta imm, J, Algun-nvr. 

